1. Field of the Invention
The invention relates to a co-axial insertion-type connector, and in particular to a co-axial insertion-type connector designed in accordance with DIN 47 223, and to a co-axial insertion-type connection formed by two such co-axial insertion-type connectors.
2. Description of Related Art
Standardized under DIN 47 223 is a co-axial insertion-type connector whose center conductor is of an outside diameter of approximately 7 mm and whose outer conductor is of an inside diameter of approximately 16 mm Co-axial insertion-type connectors to DIN 47 223 are therefore also referred to as 7/16 connectors. Because of the specific ratio between the diameters and with air as a dielectric, a characteristic impedance of approximately 50 Ω is obtained between the insertion ends of the center and outer conductors.
A co-axial insertion-type connector designed in accordance with DIN 47 223 in the form of a co-axial plug has, at the insertion end, an end of the center conductor which is in pin form and which is inserted in a corresponding end, in socket form, of the center conductor of a co-axial insertion-type connector in the form of a co-axial coupler. When so inserted, the outer conductor of the co-axial plug makes contact with the outer conductor of the co-axial coupler in both the axial and the radial directions in that the tubular end of the outer conductor of the co-axial plug is pressed against an annular step which is formed by the inner side of the outer conductor of the co-axial coupler. The axial force required to do this is applied by means of a ring nut which is rotatably mounted on one of the insertion-type connectors and which is screwed onto an external thread provided on the other, corresponding, insertion-type connector. This screwed connection at the same time serves to secure the co-axial insertion-type connection against coming loose in an unwanted way. A co-axial insertion-type connector of this kind is known from, for example, DE 43 00 243 C1.
To keep intermodulation in the region of the co-axial insertion-type connection as low as possible, extremely low signal to noise ratios are laid down for some of these connections and these can only be achieved by pressing the two co-axial insertion-type connectors making up a co-axial insertion-type connection against one another under very high axial forces. When base stations of mobile telephone networks are being wired up for example, it is necessary for the ring nut of a co-axial insertion-type connection of this kind to be tightened to a torque of up to 35 N-m to achieve the signal to noise ratio called for. The only way of ensuring that a co-axial insertion-type connection of this kind can be reliably assembled in this way is therefore by the use of a torque spanner of a sufficiently large size, which involves not inconsiderable effort and expense.
Also, there are known from U.S. Pat. No. 6,837,754 B1 adapters by which a plurality of cables can be connected, as a group, to a terminal stud of a transformer. Each such connection comprises an annular coupling body against which an annular coupling body belonging to the associated adapter is clamped to make the connection. The surfaces for contact of the coupling bodies are provided with projections and depressions in which corresponding depressions and projections on the mating member respectively engage. The intention is thereby to make the area of contact between the two contacting bodies as large as possible.